The present invention is to reduce the sound energy emanating from the interaction of the eviscerating device with the viscera, lungs and other contents of the body cavity of poultry and the like during the process of evisceration. This is done by confining the undesirably high noise level to the interior of the carcass. The primary pathway by which sound escapes to the surrounding area is through the posterior opening of the fowl around the eviscerating tool or lung removal device. Noise produced by operation of these devices results primarily from three sources. One source is the high velocity turbulent air flow through the narrow opening between the vacuum nozzle of the device and the body tissue. Another noise source is the vibration of tissues resulting from the Bernoulli effect (reduced pressure in the region of high velocity air flow). The third source of noise is turbulent flow of air entering the body cavity of the fowl to replace air being removed by the vacuum nozzle. Bernoulli effect and consequent tissue vibration occurs near the point of contact between the mouth of the vacuum nozzle and the tissue being removed and at the opening of the body cavity between the tissue at the margin of the opening and the barrel of the eviscerating device.
An object of the present invention relates to a process for sealing the posterior opening of the fowl during the suction process to prevent the escape of undesirable noise. The sealing process is accomplished by introducing a cone-like structure formed in such a way as to seal the opening while permitting the vacuum nozzle to reach tissue to be removed from the body cavity. The instrument permits successful sealing and tissue removal from poultry and the like varying greatly in size and weight. Size flexibility is accomplished by increasing the perimeter of the cone-like structure at the point of contact with the posterior opening of the fowl in proportion to the increasing depth to which the vacuum nozzle must reach as fowl size increases.
Another object of the present invention is the introduction of air into the body cavity of the fowl to replace air being drawn out by the vacuum process. This air, introduced at atmospheric pressure, is routed into the cavity through a nozzle adjacent to and attached to the vacuum nozzle. The source of the replacement air is a large air reservoir at atmospheric pressure to ensure adequate volume of replacement air flow while ensuring that noise generated by the air flow does not reach the work area outside of and surrounding the fowl being worked upon.
The features of the noise reducing method which are unique are that of providing a seal between the cone-like attachment and the tissue at the posterior opening of the fowl and the provision of a supply of air at a rate and in a quantity sufficient to replace the air removed by the suction process. Although air injection has been a feature of other eviscerating devices and methods, the purpose of injected high-pressure, high-velocity air in these cases has been to dislodge tissue to be removed and not to replace air drawn out by the vacuum, as in the present case.
With the foregoing and other objects in view the invention will be more fully described hereinafter and more particularly pointed out in the appended claims.